Pulley-grinding machine



W. C. BARNHART.

PULLEY GRINDING MACHINE.

APPLlCATlON FILED DEC. 10, 1918.

1,394,704 Patented Oct. 25, 1921.

Y 25 INVENTOR ATTORNEY PATENT oEETc WALTER C. BARNHART, F SEATTLE, WASHINGTON.

lPULLEY-GRINDIDTG MACHINE.

aaanoa.

Specification of Letters Patent. Patem'djdl ([Dmb. 25, 1921.

Application filed. December 10, 1918. Serial No. 266,031.

To all whom 2'2? may concem:

Be it known that I, WALTER C. BARNHART, a citizen of the; United States, residing at Seattle, in the county of King and State of lVashington, have invented certain new and useful Improvements in Pulley-Grinding Machines, of which the following is a specification.

This invention relates to grinding inachines and, more especially, to improvements in the construction of a machine of the character shown and described in U. S. Patent No. 1,169,377, issued to me January 25, 1916.

The object of the present invention is the perfecting of grinding machines of the referred-to type for the .purpose of rendering them more eflicient in operation, more conveniently adjusted and capable of performing functions unattainable by devices hitherto in use.

With these ends in view, the invention consists in the novel construction, adaptation and combination of parts, as will be hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a plan view of my improved grinding machine shown applied to grinding a'pulley. Fig. 2 is an end elevational view of the same. Fig. 3 is a detail vertical section'showing the abrasive wheel and de-- vices for adjustably supporting thesame,

- the wheel, arbor and holder therefor being shown in different relative positions with 85 respect to the supporting means therefor from which they are representedv in the preceding views. Fig. 4 is a view, shown somewhat diagrammatically, of a portion of a pulley face and an abrasive wheel to illuse trate the effect of the wheel when in various angular positions with respect to the work.

eferring. to the drawings, the numeral 6 designates a shaft upon which is secured a pulley 7 which is to be ground and isro- 15 tated, as indicated by arrow m, as by means of a power-driven belt 8 passing. about a pulley 9 upon the shaft 6.

According to the present invention, I provide a grinding wheel 10, made of a-suitable abrasive material, preferably of the type conventionally known as a cup wheel. This wheel is rigidly secured to 'the. screwthreaded end 11 of ashaft 12, as by means of a nut 13. Said shaft is journaled in hearing boxes 14, 14 0f a holder '15 and is secured against axial movement toward the threaded holes provided in the holder 15 work by means of an extensible set collar 16. The shaft, however, is held against axial movement away from the Work by means of anti-friction thrust bearings 19 interposed between the box 14 and a set collar 17 which is rigidly secured tothe'shaft.

Said holder is formed or provided adjacent its forward end with trunnions 15 which are journaled in spaced lugs 18 provided on a base plate 20. 21 represents screws extending through slots 22 provided in standards 22 extending upwardly from said base plate and engaging in 70. for securing the same at selected tilted. positions. The base plate 20 is provided at its underside with a circular recess 20 to receive a correspondly shaped boss 23 provided upon a carriage 23, and to which said base plate is secured in adjusted rotary positions by means of bolts 24 extending through arcuate slots 20 of-the plate to engage the carriage. Said carriage is provided in its under side with a dove-tail way 25 to receive a rib 26 provided on a bed plate 27, the latter being arranged to be rigidly secured to a supporting framework, suchas 28, as by means of bolts 32. 30 represents an adjusting screw for regulating the plate 20 to carry the abrasive wheel 10 toward or from the work, 31 is a feed screw actuated, as by a crank-handle 31 to impart movements to the carriage and associated parts during the operation of the machine. As illustrated, the abrasive wheel 10 is preferably of a f substantially. cylindrical 1 shape with a truncated conical extremity 'to provide an annular surface "10 by which the grinding or abrading operation is a directly accomplished.

In operation, the base plate 20 carrying the holder 15 is first advanced by means of the screw 30 to within a short distance of the pulley'7, which is to have its periphery" ground. The holder 15 and plate 20 are then adjusted to present the axis of the abrasive wheel 10 in suitable. ,angular relations to the work in both vertical and horizontal planes. After being thus regulated, the plate 20 is further advanced to engage the wheel with the work, whereupon the plate with the car riage is fed laterally, or in a direction parallel to the shaft 6, through the medium of the screw 31.

When the wheel encounters the face'of the pulley and with the letter rotatin in the direction denoted by arrows at in igs. 1 and 2, the wheel which is engaged at one side of its abrading face 10 will be caused to rotate in a direction indicated by arrows y in the views, but with the face 10 Q thereof at a different s eed than that of theperiphery of the pul ey by which it is driven.

The relative speeds of the engaging surfaces of the pulley and wheel may be controlled by regulating the angularity of the taxis of the abrasive wheel with respect to a plane tangential of the pulley where contacted by the abrasive wheel. This will be understood from an inspection of Fig 4 wherein 7 represents a pulley surface an a-b the axis of the abrasive wheel 10 which is caused to have its tapering surface 10 brought against the pulley surface.

, Thearrows a: and y, respectively, indicate the directions in which the wheel and pulley is adjusted to engage the pulley in the angle between the referred-to contacts, as at 9-41, for example, then the engaging wheel surface will be driven at a slower speed than the pulley periphery with a consequent grinding action.

From the foregoihg explanation,it is apparent that by regulating the angularity of the wheel axis to the pulley-face to engage the latter at a selected plane upon the wheel and within the angle inclosed by 0-d and e--/, the rotation of the wheel with-respect to the pulley may be regulated. Such regulation of the wheel to afford dilferentrelative speeds of the same with respect .to the pulley speed is an important function of the present invention and should be taken advantage of to furnish speeds most effective for the so-called roughing and finishing cuts as well as in adapting the speed of the wheel to be suitable for grinding metals of different degrees of hardness or density.

While I have illustrated and described my invention as applied to grinding a pulley, it may advantageously be employedv in analogous work such, for example, as grinding a the surfaces of beveled wheels or disks such as the face-plates of lathes.

l/Vhat I claim, is

In a machine for grinding the face of a pulley, an abrasive Wheel, a shaft for said wheel, a holder provided with journal bearings for said shaft, a base plate provided with upwardly extending lugs and standard elements, having a-rcuate slots therein cenv tering on said lugs, means provided'adjacent the forward end of said holder for tiltably connecting the same to "said lugs, meanscarriedby the holder extending through said standard slots for securing the holder in adjusted angular positions, a carriage movable parallel to the axisof the pulley, and means for connecting thebase plate to the carriage for both rotary and rectilineal movements.

Signed at 'Seattle, Washington, this 5th 

